Method of sealing metal into glass or other vitreous material.



No. 832,302. 'PATENTED OCT. 2, 1906.

G. A. ERNST. 4

METHOD OF SEALING METAL INTO GLASS OR OTHER VITREOUS MATERIAL. APPLICATION FILED JUNE 12. 1903.

Figl iwwj 5 Exhaust git/messes: lrwoencorz Carlfl.Elr-nsC, WW by M5 ful CARLA. ERNST, OF SCHENECTADY,

ELECTRIC COMPANY, A CO PATENT OFFICE.

NEW YORK, AssieNoR TO GENERAL RPORATION or NEW YORK.

METHOD OF SEALING METAL INTO'GLA SS OR OTHER VITREOUS MATERIAL.

Specification-of Letters Patent.

latented Oct. 2, 1906.

Application filed June 12, 1908. Serial No. 161.165.

To all whom it mag/concern:

Be it known that I, CARL A. ERNST, a citizen of the United States, residing at Schenectady, in the county of Schenectady and-State of New York, have invented certain new and useful Improvements in Methods of Sealing Metal into Glass or other Vitreous Material, of whichthe following is a specification.

My invention-relates to the sealin of metal into glass or other vitreous materia and has for its articular object the production of a n1onlea g joint between the metal and the ass.

g The invention is therefore particularl usecandescent lamps, mercury-lam s or rectifiers, X-ray tubes, and the like. 11 case it is desired to seal a leading-in wire into glass I first maintain the wire in a vacuum and heat the wire while in the vacuum, so as to drive ofi the gases which by the action of heat are set free from the surface of the wire. These gases are withdrawn by the exhaust or air ump as fast as set free. When gas is no onger driven off in ap reciable quantity, the wire when in a heate condition and while still in vacuum is coated with the glass and the whole then allowed to cool. By this operation an exceedingly tight joint is formed between the glass and the wire.

The features of novelty which constitute myinvention I have pointed out with particularity in the appended claim, while in the accompanying drawings I have represented certain means for carrying my invention into operation.

In the drawings, Figure 1 represents the first stage of coating a wire with glass; Fig. 2, a succeeding stage, and Fig. 3 a portion of the wire thus coated.

My invention is particularly useful in connection with oxidizable metalsuch, for example, as nickel-steel or the likeof such composition as to have a sultable coefficient of ex ansion. In sealing such a wire into lass first connect its ends to two platinum ea'ding-in wires. In Fi 1 the nickel-steel wire is indicated at 1 an the platinum leading-in wires at 2 and 3. The leading-in wires are then sealed through the opposite ends of in connection with leading-in wires or inwith hydro (1'1 or some other as before proceedin wit the exhaustion; ut this, however, t ough advantageous, is not essential. After the apparatus has been arranged as shown in Fig. l the tube 4 is exhausted, while at the same time current from a suitable source is the medium of the leading-in conductors 2 and 3. The wire is brought to a white heat, thereby causing gases to be given off, which gases are removed b the exhaust-pump as ast as they are set ee. When ractically no further ases are given off anrf while the wire 1 is sti 1 hot, the glass tube is heated by a suitable torch at points a short distance apart until the glass fiows around the wire. It will be evident that the softening of the glass by the torch allows the external pressure of the atmosphere to contract the softened portions about the wire 1. When this operation is completed, the glass tube 4 has passed through the wire 1 through assumed the condition shown in Fig. 2, in

amp e, at 6 7 8, &c.) The heating-current passing through the wire 1 is then discontinued and the air-pump turned ofi", On cooling, the glass tube is broken at suitable inter-- va s as, for example, along dotted lines indicated at 9 and 1O and the wire out between the points, which are sealed to the glass. The resulting short sections of wire, such as at 11 in Fig. 3, with the closely adherent glass coating 12, may then be sealed into the glass envelop of any desired apparatus, such as incandescent lamps, mercury-lamps, or other devices of similar character.

By utilizing the sealing-in method above described a wire, such as lron or nickel-steel, does not become covered with oxid, the presence of which would interfere with the tightness of the seal. Moreover, inasmuch as the wire is not cooled before it is covered with glass the wires have no chance to absorb gases anew, which on reheating by the 'passage of current during normal operation would give 013 bubbles, thus impairing the being in intimate contact with the Wire and joint between the wire and the glass. forming a gas-ti ht joint therewith.

What I claim as new, and desire to secure In Witness w ereof I have hereunto set by Letters Patent of the United States, is my hand this 10th day of June 1903.

5 As an article of manufacture, a metal wire, CARL A. ERNST.

from which occluded gases have been re- Witnesses: moved, and a coatin of glass about said wire BENJAMIN B. HULL, of substantially orm thickness, said glass HELEN ORFORD. 

